Polymerase chain reaction (PCR):
A process that repeatedly replicates a selected segment of DNA in order to generate thousands of copies of a specific strand
Substances involved in PCR:
DNA segment - A piece of DNA extracted from the cell of the embryo, containing the DNA segment of interest
Primers - Short pieces of DNA that attach to the ends of the segment of interest through complementary base pairing. Two primers are made; one attaches to the beginning of the segment of interest, the other attaches to the end of the segment of interest
Nucleotides - Made up of a sugar, phosphate, and base. There are four types of bases (adenine, thymine, guanine, and cytosine)
DNA polymerase - A complex of proteins that attaches to the primer and adds nucleotides in the direction of the segment of interest through complementary base pairing
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Step Three: The thermocycler reduces the temperature to 50 degrees Celsius/122 degrees Fahrenheit. At this temperature, the two primers attach on to the two strands of DNA. One primer attaches on the first strand of DNA, the beginning of the segment of interest. The second primer attaches to the second strand of DNA, at the end of the segment of interest.
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Step Four: The thermocycler heats up once again to 72 degrees Celsius/161.6 degrees Fahrenheit. This triggers the DNA polymerase, and it attaches where the primers are located. The DNA polymerase uses complementary base pairing (adenine-thymine and cytosine-guanine) to copy the segment on each strand of DNA. Once the DNA polymerase reached the end of the strand, it drops off.
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